Connect with us

DC power supply with different V out

Discussion in 'Power Electronics' started by DavidV, Dec 5, 2017.

  1. DavidV

    DavidV

    16
    0
    Dec 5, 2017
    I am working on a project with my high school physics students and we need to have a single battery but need to supply different voltages to different devices. I was hoping to make something that would have a 9.6V battery (rechargable NiMH 2000mAh) that can provide three levels of output 9V, 5V, and 3V. I would prefer something stable with more than just resistors in series and parallel. Maybe incorporating voltage regulators or something like that.

    Could anyone provide a relatively simple circuit diagram that would be assembled by students with basic circuit knowledge?

    Thanks,
    David
     
  2. KMoffett

    KMoffett

    687
    66
    Jan 21, 2009
    How muck current is required for each 9v, 5v, and 3V?

    Ken
     
  3. davenn

    davenn Moderator

    13,294
    1,758
    Sep 5, 2009
    look on eBay .... there's a zillion buck regulators to choose from
     
  4. DavidV

    DavidV

    16
    0
    Dec 5, 2017
    Thanks,

    Small currents for most applications. It will be for things like IR transmitter/receiver, thermistors, photocells, LEDs. The only two items that may draw more current is a small nichrome coil heater and small electromagnet.

    Nothing will be running at the same time except trans/rec and LED/photocell pairs. So things like the electromagnet and heater will not be running at the same time and nothing will be on for more than a few seconds. The heater and thermistor will also be on together.
     
  5. Bluejets

    Bluejets

    3,489
    706
    Oct 5, 2014

    Attached Files:

  6. DavidV

    DavidV

    16
    0
    Dec 5, 2017
    I didn't see many that have multiple outs. I could connect them in parallel all set at different outputs.
    Those look good but can't wait for delivery. I will dind something similar with quickly turnaround.

    Thanks.
     
  7. duke37

    duke37

    5,231
    718
    Jan 9, 2011
    9.6V to 9V seems too close. Would 8V do?
    Do not tap the battery or you will get some cells discharged too far and some overcharged.

    A single buck convertor could be switched for different output voltages.
     
  8. kellys_eye

    kellys_eye

    4,281
    1,144
    Jun 25, 2010
    Given the low current requirements and short time intervals a simple resistor/zener arrangement would do just as well as anything. Trying to keep it simple here.......
     
  9. davenn

    davenn Moderator

    13,294
    1,758
    Sep 5, 2009
    no there are not
    you will have to buy 3 of them and set each one for your required voltage .... they are dirt cheap, only a few bux each
     
  10. Alec_t

    Alec_t

    2,686
    710
    Jul 7, 2015
    You could try this switch-selectable output regulator :-
    SwitchedRegulator.PNG
    The P-MOSFET (M1) should preferably be a logic-level type. Rload is just a simulated load. C1 suppresses noise on the output. Almost any comparator could be used instead of the LM339 (a quad package, only a quarter of which is used here). Any unused comparator inputs should be grounded.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-